Bulkhead leaks - Wet fusebox

Derek UK · Jan 25th, 2014, 13:28

This is a sort of follow up to Coaster's bulkhead foam replacement. Sometime back, can't find the post, it was mentioned that there had been a Volvo recall/Workshop tip, that behind this insulation there was, on some cars, a hole that allowed water into the heater air box cavity. It was advised that it should be sealed. Whereabouts is this hole? The air box itself must have drains somewhere, down into the A posts has been mentioned I think, and these must be prone to getting blocked with dirt, leaves etc. Where are the drains and how can you check them for blockages? The pic attached is from a Mike Brace thread on a potential restoration and shows the air box cut open, I hope he doesn't mind me using it. It shows a large hole in the inner panel. Can't think what would be routed through or fitted here except a large bore drain pipe. This looks to be nicely positioned to cause the very common wet fuse box if whatever is in this hole isn't sealing properly. Comments welcome and I'm sure those with the fuse box problem would appreciate a potential cure, if windscreen seal leaks have been ruled out.

Clifford Pope · Jan 25th, 2014, 17:28

Is that the wiper motor hole? I can't picture where exactly that picture is taken, but a perished rubber seal on the wiper motor housing is a known cause of leaks.

Volvorama · Jan 25th, 2014, 22:13

I think it's wiper motor hole too.

Derek UK · Jan 26th, 2014, 13:20

Yes, a hole for the wiper motor shaft sounds good. For CP, the whole of the outer bulkhead, the surface that the insulation is stuck to, has been removed here exposing the rear part of the air box. Behind that is the inside of the car. Questions not answered are, how does the water drain away/where are drains and does anyone remember the post that mentioned the Volvo advice about sealing the hidden hole?

Clifford Pope · Jan 26th, 2014, 15:32

The water drains away to the right of your picture, in a void at the rear of the wing. and comes out at the front end of the cill. if you look under the cill there is a slot at the front, with the front outer section of cill detached from the main structure, like a flap of metal.
Try pouring water down from the scuttle, and that is where it should emerge.
It can through rust in the door pillar, emerge inside the car over the fuse box.
Also I think, but am vague as to the details, if it gets blocked at the bottom it insted flows inside the main section of cill. This is not necessarilly bad, as long as the little drain slots along the cill are kept clear. There are also access points (not I think on later cars) on the inner sides of the cills in the footwells.

The hole in the photo, if it is for the wiper motor, should be sealed by the motor itself as its output shaft housing is fed through the two skins of the bulkhead. You can see this looking up from inside the car - it's a sort of squishy rubber grommet sealing the gap between the hole and the motor.

There is I think a similar hole on the other side for the bonnet release cable, also prone to leaks.

Jan 25th, 2014, 13:28	#1
Derek UK VOC Member Last Online: Yesterday 21:31 Join Date: Jul 2006 Location: Chatham	Bulkhead leaks - Wet fusebox This is a sort of follow up to Coaster's bulkhead foam replacement. Sometime back, can't find the post, it was mentioned that there had been a Volvo recall/Workshop tip, that behind this insulation there was, on some cars, a hole that allowed water into the heater air box cavity. It was advised that it should be sealed. Whereabouts is this hole? The air box itself must have drains somewhere, down into the A posts has been mentioned I think, and these must be prone to getting blocked with dirt, leaves etc. Where are the drains and how can you check them for blockages? The pic attached is from a Mike Brace thread on a potential restoration and shows the air box cut open, I hope he doesn't mind me using it. It shows a large hole in the inner panel. Can't think what would be routed through or fitted here except a large bore drain pipe. This looks to be nicely positioned to cause the very common wet fuse box if whatever is in this hole isn't sealing properly. Comments welcome and I'm sure those with the fuse box problem would appreciate a potential cure, if windscreen seal leaks have been ruled out.

Jan 25th, 2014, 22:13	#3
Volvorama Too many cats Last Online: Aug 24th, 2023 09:02 Join Date: Aug 2011 Location: Birmingham	Yes I think it's wiper motor hole too. __________________ Mark

Jan 25th, 2014, 17:28	#2
Clifford Pope Not an expert but ... Last Online: Yesterday 08:24 Join Date: Dec 2001 Location: Boncath	Is that the wiper motor hole? I can't picture where exactly that picture is taken, but a perished rubber seal on the wiper motor housing is a known cause of leaks.

Jan 26th, 2014, 13:20	#4
Derek UK VOC Member Last Online: Yesterday 21:31 Join Date: Jul 2006 Location: Chatham	Yes, a hole for the wiper motor shaft sounds good. For CP, the whole of the outer bulkhead, the surface that the insulation is stuck to, has been removed here exposing the rear part of the air box. Behind that is the inside of the car. Questions not answered are, how does the water drain away/where are drains and does anyone remember the post that mentioned the Volvo advice about sealing the hidden hole?

Jan 26th, 2014, 15:32	#5
Clifford Pope Not an expert but ... Last Online: Yesterday 08:24 Join Date: Dec 2001 Location: Boncath	The water drains away to the right of your picture, in a void at the rear of the wing. and comes out at the front end of the cill. if you look under the cill there is a slot at the front, with the front outer section of cill detached from the main structure, like a flap of metal. Try pouring water down from the scuttle, and that is where it should emerge. It can through rust in the door pillar, emerge inside the car over the fuse box. Also I think, but am vague as to the details, if it gets blocked at the bottom it insted flows inside the main section of cill. This is not necessarilly bad, as long as the little drain slots along the cill are kept clear. There are also access points (not I think on later cars) on the inner sides of the cills in the footwells. The hole in the photo, if it is for the wiper motor, should be sealed by the motor itself as its output shaft housing is fed through the two skins of the bulkhead. You can see this looking up from inside the car - it's a sort of squishy rubber grommet sealing the gap between the hole and the motor. There is I think a similar hole on the other side for the bonnet release cable, also prone to leaks.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)